Kinetic parameters for wild-type CCT236 and active site mutants of CCT236
Parameters were obtained from the plots of initial velocity versus substrate concentration shown in Fig. 6, using GraphPad Prism 4 software. The Km and Vmax values are derived from the best fit to the Hill equation (see Fig. 6, legend) ± S.E. of the fit. The wild-type Vmax value from the CTP curve is more accurate, because the CTP concentration was subsaturating in the phosphocholine curves. Units for Vmax are nanomoles of CDP-choline formed (min−1) (mg CCT−1). Units for K* are in millimolar.